Dodge, roll, and shoot your way through a constantly evolving labyrinth of firearm folly in Enter the Gungeon by Dodge roll Games. Choose from several unlikely heroes bearing personal burdens, be it a forgotten past or haunting betrayal. Venture into the mysterious ever-changing Gungeon to seek a mythical gun to shoot away your characters’ sorrows across six treacherous zones filled with shielded enemies and screen-filling bosses. Master an arsenal featuring hundreds of procedurally generated guns with zany capabilities, from flamethrowers and energy cannons to blast cannons with bouncing bullets. React on the fly by flipping tables for cover and rolling to avoid a ridiculous barrage of incoming fire in this mashup of arcade shooters, high-stakes dungeon crawlers and absurd sci-fi motifs. Reload and ready up lock, stock and barrel for this frenetically fun barrage of bullets, buffs and boss battles promising the perfect gun and redemption...one room at a time. Who knows what firepower fantasies or secrets await discovery next in Enter the Gungeon’s wealth of weapons? The Gungeon beckons!

@Fusha

Version: any platform, latest version (v2.1.9)

I hope you like shooting things, because that's what you're gonna be doing for pretty much the entire game! Enjoy the variety of weapons and items the game throws at you, and see how far you can get through all the dodge-rolling action!

Progress is measured by the furthest numbered chamber (floor) reached with any of the four main characters, and which character to use is up to you. There are five numbered chambers, and if you beat the boss of the fifth chamber, you win! Following a win, additional progress can be made by playing one of the three remaining characters, and so on. Only runs played after your win count for this additional progress.

Tiebreakers: characters won, then your progress in your best run with your current character, then your run count up to and including that run, then your time at the end of that run.

Time limit: 5 hours. You can do the tutorial -- the room directly up from where you start -- without starting the timer, to get used to the mechanics and the controls. You should start the timer after going through the central door with the two guards. The game has a lot of pop-culture references in its item descriptions and elsewhere, so if you want to take some time to read the Ammonomicon, feel free to pause the timer while doing so.

The use of the shortcut mechanic is not permitted -- in other words, you must always start each run from chamber 1.
Please make sure that, in options -> gameplay, «Loot profile» is set to «Gungeons and Draguns» and «Increase speed out of combat» is disabled.
Also, if you've played the game before, you have to change your save slot to a brand new one before starting -- you can do this in options -> gameplay -> scroll all the way down.

The game lacks a manual, but I will make up for it by providing some hints and important information below!

Tips & Prohints
Each chamber has a shop and two treasure rooms with a chest each. Brown chests give you the worst rewards, then blue, then green. You might not have a key for every chest, so choose wisely.
If you have fewer than two blanks at the start of a chamber, your blanks get replenished to 2.
Bullet components -- such as the very expensive Prime Primer you can buy in the shop -- won't do anything for you as far as this challenge goes, so don't bother with them. If you find a room with a minecart puzzle or chasm and a seemingly unreachable item on the other side, trying to get those would be a waste of time too.
Picked up a passive item you don't like? You can drop it by opening the map, then selecting the item under the map, then selecting «drop». Dropping guns and active items is easier -- there are dedicated keys to do that, which you can find in your keybind settings. This is also how you sell your items, if you find a particular NPC...
Early on, you will become able to unlock new guns and items -- but choosing not to bother with unlocking more stuff could also be a valid strat. When unlocking guns and items, you're not adding them to your inventory, you're adding them to the pool of drops that you might randomly find in your runs.
Have you stumbled upon something that might possibly lead to a secret chamber? If so, going through it won't count towards your progress, but it might net you some items or guns that will help you further along... But, more likely, it will just lead to more deaths!
If you somehow managed to unlock additional characters, you can't use them, sorry.
If you're playing on the Nintendo Switch, you should probably change your graphics preset in the game's options to «Speed», otherwise you might experience significant slowdown.
If you find yourself on fire, roll to put it out!
If you're playing with a keyboard, you can use the number row keys to quickly swap weapons, just like in your favourite FPS games.
Obscure but important mechanics
Some choices you make will cause you to be «cursed». The more curse you accumulate, the higher the chance of red enemies spawning, which have higher HP and deal double damage. Drop rates get decreased too. If you accumulate too much curse, very bad things will happen!
Some items, such as the cigarettes, give you «coolness». The more coolness you have, the higher the chance of a bonus items spawning, such as health. It also decreases your active item cooldown. Coolness and curse are both hidden stats.
Sometimes, when equipping an item, an upward arrow will show above your character. That means your item has a synergy with another one of your items, which changes one or both of them in some way, often making them more powerful. Your ammonomicon will show which item the synergy is with.

1st) Fusha - Progress: 4 Characters Won - Runs: 4 - Time: 03:08:13
2nd) Marcman_59 - Progress: 4 Characters Won - Runs: 5 - Time: 04:02:34
3rd) ReturnOfOctobot - Progress: Chamber 4 - Runs: 9 - Time: 02:35:08
4th) Kythias - Progress: Chamber 3 - Runs: 3 - Time: Infinite
5th) FullCup - Progress: Chamber 3 - Runs: 9 - Time: 1:38:52
6th) Tater84 - Progress: Chamber 3 - Runs: 9 - Time: 2:09:55
7th) Lovenfloofen - Progress: Chamber 3 - Runs: 15 (25) - Time: 03:08:13